Cloning of human picobirnavirus genomic segments and development of an RT-PCR detection assay

Nearly full-length genomic segments 2 and a partial-length genomic segment 1 of human picobirnavirus were cloned and sequenced. The clones were derive d from viruses obtained from human immunodeficiency virus (HIV)-infected pa tients in Atlanta, Georgia (strains 3-GA-91 and 4-GA-91) and a nonHIV-infec ted person from China (strain 1-CHN-97). The picobirnavirus genomic segment s lacked sequence similarities with other viral sequences in GenBank and EM BL. Comparison of genomic segment 1 from a human and a rabbit picobirnaviru s identified a region of 127 nucleotides with 54.7% identity. The genomic s egments 2 of the 4-GA-91 and 1-CHN-97 strains had 41.4% nucleic acid identi ty and 30.0% amino acid similarity and contained amino acid motifs typical of RNA-dependent RNA polymerase genes. Reverse transcription-PCR detection assays were developed with primers targeted to the genomic segments 2 of st rains 4-GA-91 or 1-CHN-97. Picobirnaviruses related to the China strain wer e the predominant viruses detected in stool samples from people in four cou ntries on three continents. Picobirnaviruses were detected in samples from two outbreaks of gastroenteritis in long-term elder care facilities but wer e not determined to be the primary pathogen. Our findings support the view that picobirnaviruses constitute a distinct family of viruses. (C) 2000 Aca demic Press.